Don’t ignore the massive destructive carbon footprint of that big 747 and all the support vehicles.
I don’t think it was an absentee ballot. I think it was early voting, which Illinois allows. The wife and I did the same thing here in Granite City (Southern Illinois). And for early voting in Illinois, you have to show a photo id. I recall the news saying that BO showed one, and joked about his hair being grayer. I think he was passing through.
Not nearly as much as the tens (hundreds?) of millions of dollars that we spent for him to take Air Force 1 all over the country for campaign fund raisers and campaign rally stops.
Obama Casts Vote, Becomes First President To Cast His Ballot Early